Run of 2018 awards help Rice bioengineer Rob Raphael advance cochlear implant research

Rice University could be where hardware, software and modeling come together to conquer a challenge that has intrigued and frustrated scientists for decades: The creation of devices small enough and sensitive enough to provide relief to those who are hard of hearing or even deaf.

Proposals by Rice’s Rob Raphael, an associate professor of bioengineering at the BioScience Research Collaborative, won five awards in 2018. He expects they will help solve conundrums that stand in the way of better hearing for many people – including himself.

Raphael, whose lab specializes in research that helps the hearing-impaired, has had a cochlear implant for five years. “After I got my implant, I expanded my research beyond just the hair cells in the inner ear into what’s going on in the brain and the cochlea,” he said.

Rice bioengineer Rob Raphael and his colleagues have won five grants this year to advance the cause of technology for the deaf and hard of hearing. Photo by Jeff Fitlow

The first award, a seed grant from the Dunn Foundation early this year, is helping Raphael and Francois St-Pierre, an assistant professor of electrical and computer engineering at Rice and of neuroscience at Baylor College of Medicine, develop proteins that sense dynamic voltage changes in inner-ear stereocilia, part of the fine hair cells translate mechanical sound pressure in the ear into electrical signals for the brain.

The second award is a prestigious National Institutes of Health R01 grant shared with Raphael by colleagues at the University of Chicago. It focuses on the vestibular inner ear that stabilizes vision and posture and also has implications for hearing. The grant is allowing Raphael’s lab to enhance its already sophisticated computer models of ion transport and neuronal spiking in the inner ear.

Those grants prompted Raphael to think about how their collective research can be applied to cochlear implants, electronic devices that directly stimulate the inner ear’s auditory nerve when the cochlea is damaged.

“The major problem with current cochlear implant devices is that they are based on technology that is over 30 years old, and only have a maximum of 22 channels,” he said. “That’s nowhere near enough to facilitate natural sound that relies on 4,000 inner hair cells.”

Meetings this year with scientists who have training in implants — as well as auditory neuroscience, speech perception and devices that connect directly to neurons — convinced Raphael that improvements are not only possible, they can also be accomplished with the expertise already centered in Houston. That goal aligns well with Rice’s Vision for the Second Century, Second Decade, which encourages engagement with the city, especially with other Texas Medical Center institutions.

The National Science Foundation (NSF) sees the potential as well. A group led by Raphael was one of the few chosen from more than 300 applicants to receive a planning grant to create an NSF Engineering Research Center (ERC). This third award will allow Raphael and his group to build engineering capacity and engage stakeholders as they prepare a comprehensive proposal to bring such a center to Rice, with a decision due in 2020.

Their proposal, if accepted, would establish an ERC to advance the state of the art in auditory bioengineering and rehabilitation, with a goal of attracting enough industry support to make the center self-sustaining in 10 years.

The various threads contributing to the bid will incorporate bioengineering, neuroengineering and cognitive science. “The general goal is to support convergent research that introduces new technologies and approaches to understand and restore auditory function and alleviate the societal impact of hearing loss,” Raphael said. “The mission we’ve crafted for the ERC statement is to revolutionize auditory rehabilitation across one’s lifespan and to train a diverse engineering workforce to fulfill this ambitious goal.”

“I’ve also come to realize that while the cochlear implant is supposed to be the most successful of all neuroprosthetics, it’s been a complete failure socially,” Raphael said. “Only 10 percent of the people who should get it actually do.

“So even though we have the vision to build the next-generation device, we also have to work with the industry and insurance companies to help it reach all the people it should. I consider this an ethical responsibility,” he said.

Raphael noted a co-principal investigator on the ERC bid, Lina Reiss of the Oregon Health and Science University, observed that growing up with a different native language has ramifications for the hearing-impaired. “She has data showing that when you put cochlear implants in children from Spanish-speaking families, they don’t do as well as those from English-speaking families in the U.S.,” he said. “This is startling, and we plan to figure out how to improve this so all children with cochlear implants can fulfill their potential.”

Raphael credits Rice colleague and co-investigator Simon Fischer-Baum, an assistant professor of psychological sciences who studies language, for inspiring him to think about top-down as opposed to bottom-up aspects of language processing.

“Simon asked how much acoustic cues are taken into account when companies program cochlear devices,” Raphael said. “As far as I’ve been able to tell, they’re really not. It appears to be direct processing of the speech signal done by engineers with a bottom-up mentality.

“What I’ve started to realize is that a field I never knew much about, the neurobiology of language and speech perception, has a lot of potential to improve cochlear implants,” Raphael said.

“2018 has certainly been a fantastic year,” Raphael said. “I’m very grateful to all my collaborators and the funding supporters who made these grants possible. I’m also personally grateful to Dean Reggie (DesRoches) and my chair, Jane Grande-Allen, for their warm encouragement and support to pursue the ERC planning grant, and to Phyllis McBride in the Office of Proposal Development for support.

“Hopefully, this funding will be a tipping point,” he said. “It’s been my dream for 15 years to build a premiere hearing research lab and we have the talent in Houston already, as the ‘third coast’ for biotechnology. The fact that we’re also the capital of carbon nanotechnology means we’re exactly the place to build next-generation cochlear implants.”